Configuring MPLS Detour FRR
MPLS detour FRR automatically creates a detour LSP on each eligible node along primary CR-LSP to protect downstream links or nodes.
Context
TE FRR provides local link or node protection for TE tunnels. TE FRR is working in either facility backup or one-to-one backup. Table 1 compares facility backup and one-to-one backup.
Mode |
Advantages |
Disadvantage |
|---|---|---|
Facility backup |
Is extensible, resource efficient, and easy to implement. |
Bypass tunnels must be manually planned and configured, which is time-consuming and laborious on a complex network. |
One-to-one backup |
Is easy to configure, eliminates manual network planning, and provides flexibility on a complex network. |
Each node has to maintain the status of detour LSPs, which consumes additional bandwidth resources. |
TE FRR in one-to-one backup mode is also called MPLS detour FRR. Each eligible node automatically creates a detour LSP.
This section describes how to configure MPLS detour FRR. For information about how to configure TE FRR in facility backup mode, see Configuring MPLS TE Manual FRR and Configuring MPLS TE Auto FRR.
The facility backup and one-to-one backup modes are mutually exclusive on the same TE tunnel interface. If both modes are configured, the latest configured mode overrides the previous one.
After MPLS detour FRR is configured, nodes on a TE tunnel are automatically enabled to record routes and labels. Before you disable the route and label record functions, disable MPLS detour FRR.
Pre-configuration Tasks
Before configuring MPLS detour FRR, configure an RSVP-TE tunnel.
Enable CSPF on each node along both the primary and backup LSPs.
Procedure
- Run system-view
The system view is displayed.
- Run interface tunnelinterface-number
The TE tunnel interface view is displayed.
- Run mpls te detour
MPLS detour FRR is enabled.
On the same tunnel interface, both the mpls te detour and mpls te fast-reroute commands can be run. The latest configuration overrides the previous one.
- Run commit
The configuration is committed.
Checking the Configurations
After configuring MPLS detour FRR, run the following commands to check the configurations.
Run the display mpls te tunnel command to view TE tunnel information.
Run the display mpls te tunnel path command to view TE tunnel path information on a local node.
Run the display mpls rsvp-te psb-content command to view RSVP-TE path state block (PSB) information.